Printed circuit boards are hitherto used for connection to connector terminals. Furthermore, there are some printed circuit boards which are configured to be placed so as to cover an opening of a case in order to separate the inside from the outside of the case.
A printed circuit board which is configured to be placed so as to cover an opening of a case, for example, includes a base film made of a polyimide, a copper foil placed on the base film, and an insulating layer which covers a surface of the copper foil (refer to Japanese Unexamined Patent Application Publication No. 2011-210307).